KNOWING, CHARACTERIZING AND ASSESSING SYSTEMS OF ORGANIC CROP ROTATIONS

The choice of crop rotations in organic stockless cropping systems is the first leverage used to manage technical issues (to maintain soil fertility, to control pest and weeds) and economic issues (to insure income). The RotAB project (French Casdar funding 2008-2010) implemented complementary approaches to better knowing, characterizing and assessing arable crop rotations. Their conception depends on numerous factors such as the types of soil and climate (on which depend the types of crops, yield potential, possibility of mechanical weed control…) or the economic context (existence of outlets and continuity of markets). If nitrogen supply and weed control are the most important agronomic issues of organic farmers in stockless cropping systems, phosphorus availability appears to be the next important issue for soil fertility and system sustainability

Energy analysis of organic crop systems. Impact of intensification level.

This study reveals a wide variability in the major parameters of the energy analysis applied to 44 four-year-long organic crop sequences. The intensification level of the systems in terms of the use or nonuse of organic fertilisation on cereals and of irrigation on summer crops (mainly pulses) is largely responsible for this variability. Average energy consumption ranges from 5 000 to 12 270 MJ/ha/year depending on the intensification level. Energy production varies from 35 500 to 43 950 MJ/ha/year. Since energy consumption and production both vary in the same direction with the degree of intensification, the energy gain is stable at an average value of 29300 MJ/ha/year. Energy efficiency decreases from 7.1 MJ/MJ for unfertilised and unirrigated crop sequences, to 3.5 MJ/MJ for fertilised and irrigated sequences, where soy and faba bean are among the major crops

GHRS and ORFEUS-II Observations of the Highly Ionized Interstellar Medium Toward ESO141-055

We present Goddard High Resolution Spectrograph and ORFEUS-II measurements of Si IV, CIV, N V, and O VI absorption in the interstellar medium of the Galactic disk and halo toward the nucleus of the Seyfert galaxy ESO141-055. The high ionization absorption is strong, with line strengths consistent with the spectral signature expected for hot (log T = 5-6) collisionally ionized gas in either a ``Galactic fountain'' or an inhomogeneous medium containing a mixture of conductive interfaces and turbulent mixing layers. The total O VI column density of log N ~ 15 suggests that the scale height of O VI is large (>3 kpc) in this direction. Comparison of the high ion column densities with measurements for other sight lines indicates that the highly ionized gas distribution is patchy. The amount of O VI perpendicular to the Galactic plane varies by at least a factor of ~4 among the complete halo sight lines thus far studied. In addition to the high ion absorption, lines of low ionization species are also present in the spectra. With the possible exception of Ar I, which may have a lower than expected abundance resulting from partial photoionization of gas along the sight line, the absorption strengths are typical of those expected for the warm, neutral interstellar medium. The sight line intercepts a cold molecular cloud with log N(H2) ~ 19. The cloud has an identifiable counterpart in IRAS 100-micron emission maps of this region of the sky. We detect a Ly-alpha absorber associated with ESO141-055 at z = 0.03492. This study presents an enticing glimpse into the interstellar and intergalactic absorption patterns that will be observed at high spectral resolution by the Far Ultraviolet Spectroscopic Explorer.Comment: 24 pages + 8 figures, uses aaspp4.sty. Accepted for publication in Ap

The Object Management Group Ontology Definition Metamodel

Report of a submission being made to a major international software engineering standards group, the Object Management Group which ties together OMG standards with World-Wide Web Consortium and International Standards Organization standards. Major industry bodies including IBM are collaborating, and the submission has the support of 24 companies. OMG, W3C and ISO standards strongly influence the industry, especially in combination. Colomb was a major contributor, responsible for 30% of the submission, and the primary author of the paper

Distance to the northern high-latitude HI shells

A detailed 3D distribution of interstellar matter in the solar neighborhood is increasingly necessary. As part of a 3D mapping program, we aim at assigning a precise distance to the high-latitude HI gas in particular the northern part (b \geq 55^{circ}) of the shell associated with the conspicuous radio continuum Loop I. This shell is thought to be the expanding boundary of an interstellar bubble inflated and recently reheated by the strong stellar winds of the nearby Scorpius-Centaurus OB. We recorded high-resolution spectra of 30 A-type target stars located at various distances in the direction of the northern part of Loop I. Interstellar NaI 5889-5895 and CaII K-H 3934-3968 {\AA} are modeled and compared with the HI emission spectra from the LAB Survey. About two-thirds of our stellar spectra possess narrow interstellar lines. Narrow lines are located at the velocity of the main, low-velocity Loop 1 HI shell ([-6,+1] km/s in the LSR). Using Hipparcos distances to the target stars, we show that the closest boundary of the b geq+70^{\circ} part of this low-velocity Loop I arch is located at of 98 \pm 6 pc. The corresponding interval for the lower-latitude part (55^{\circ} \leq b \leq 70^{\circ}) is 95-157 pc. However, since the two structures are apparently connected, the lower limit is more likely. At variance with this shell, the second HI structure, which is characterized by LSR Doppler velocities centered at -30 km/s, is NOT detected in any of the optical spectra. It is located beyond 200 parsecs or totally depleted in NaI and CaII. We discuss these results in the light of spherical expanding shells and show that they are difficult to reconcile with simple geometries and a nearby shell center close to the Plane. Instead, this high-latitude gas seems to extend the inclined local chimney wall to high distances from the Plane.Comment: Astronomy & Astrophysics (A&A in press

Advancing national greenhouse gas inventories for agriculture in developing countries : improving activity data, emission factors and software technology

Peer reviewedPublisher PD

Agricultural climate change mitigation : Carbon calculators as a guide for decision making

This is an Accepted Manuscript of an article published by Taylor & Francis Group in International Journal of Agricultural Sustainability on 9 November 2017, available online: https://doi.org/10.1080/14735903.2017.1398628. Under embargo. Embargo end date: 9 November 2018.The dairy industry is receiving considerable attention in relation to both its significant greenhouse gas (GHG) emissions, and it’s potential for reducing those emissions, contributing towards meeting national targets and driving the industry towards sustainable intensification. However, the extent to which improvements can be made is dependent on the decision making processes of individual producers, so there has been a proliferation of carbon accounting tools seeking to influence those processes. This paper evaluates the suitability of such tools for driving environmental change by influencing on-farm management decisions. Seven tools suitable for the European dairy industry were identified, their characteristics evaluated, and used to process data relating to six scenario farms, emulating process undertaken in real farm management situations. As a result of the range of approaches taken by the tools, there was limited agreement between them as to GHG emissions magnitude, and no consistent pattern as to which tools resulted in the highest/lowest results. Despite this it is argued, that as there was agreement as to the farm activities responsible for the greatest emissions, the more complex tools were still capable of performing a ‘decision support’ role, and guiding management decisions, whilst others could merely focus attention on key issues.Peer reviewe

The Leiden/Argentine/Bonn (LAB) Survey of Galactic HI: Final data release of the combined LDS and IAR surveys with improved stray-radiation corrections

We present the final data release of observations of lambda 21-cm emission from Galactic neutral hydrogen over the entire sky, merging the Leiden/Dwingeloo Survey (LDS: Hartmann & Burton, 1997) of the sky north of delta = -30 deg with the Instituto Argentino de Radioastronomia Survey (IAR: Arnal et al., 2000, and Bajaja et al., 2005) of the sky south of delta = -25 deg. The angular resolution of the combined material is HPBW ~ 0.6 deg. The LSR velocity coverage spans the interval -450 km/s to +400 km/s, at a resolution of 1.3 km/s. The data were corrected for stray radiation at the Institute for Radioastronomy of the University of Bonn, refining the original correction applied to the LDS. The rms brightness-temperature noise of the merged database is 0.07 - 0.09 K. Residual errors in the profile wings due to defects in the correction for stray radiation are for most of the data below a level of 20 - 40 mK. It would be necessary to construct a telescope with a main beam efficiency of eta_{MB} > 99% to achieve the same accuracy. The merged and refined material entering the LAB Survey of Galactic HI is intended to be a general resource useful to a wide range of studies of the physical and structural characteristices of the Galactic interstellar environment. The LAB Survey is the most sensitive Milky Way HI survey to date, with the most extensive coverage both spatially and kinematically.Comment: 9 pages, 5 figures, accepted for publication by Astronomy & Astrophysic

Evaluating the effects of bilingual traffic signs on driver performance and safety

Variable Message Signs (VMS) can provide immediate and relevant information to road users and bilingual VMS can provide great flexibility in countries where a significant proportion of the population speak an alternative language to the majority. The study reported here evaluates the effect of various bilingual VMS configurations on driver behaviour and safety. The aim of the study was to determine whether or not the visual distraction associated with bilingual VMS signs of different configurations (length, complexity) impacted on driving performance. A driving simulator was used to allow full control over the scenarios, road environment and sign configuration and both longitudinal and lateral driver performance was assessed. Drivers were able to read one and two-line monolingual signs and two-line bilingual signs without disruption to their driving behaviour. However, drivers significantly reduced their speed in order to read four-line monolingual and four-line bilingual signs, accompanied by an increase in headway to the vehicle in front. This implies that drivers are possibly reading the irrelevant text on the bilingual sign and various methods for reducing this effect are discussed

Characterizing the impact of urban emissions on regional aerosol particles: airborne measurements during the MEGAPOLI experiment

The MEGAPOLI (Megacities: Emissions, urban, regional and Global Atmospheric POLlution and climate effects, and Integrated tools for assessment and mitigation) experiment took place in July 2009. The aim of this campaign was to study the aging and reactions of aerosol and gas-phase emissions in the city of Paris. Three ground-based measurement sites and several mobile platforms including instrument equipped vehicles and the ATR-42 aircraft were involved. We present here the variations in particle- and gas-phase species over the city of Paris, using a combination of high-time resolution measurements aboard the ATR-42 aircraft. Particle chemical composition was measured using a compact time-of-flight aerosol mass spectrometer (C-ToF-AMS), giving detailed information on the non-refractory submicron aerosol species. The mass concentration of black carbon (BC), measured by a particle absorption soot photometer (PSAP), was used as a marker to identify the urban pollution plume boundaries. Aerosol mass concentrations and composition were affected by air-mass history, with air masses that spent longest time over land having highest fractions of organic aerosol and higher total mass concentrations. The Paris plume is mainly composed of organic aerosol (OA), BC, and nitrate aerosol, as well as high concentrations of anthropogenic gas-phase species such as toluene, benzene, and NO_x. Using BC and CO as tracers for air-mass dilution, we observe the ratio of ΔOA / ΔBC and ΔOA / ΔCO increase with increasing photochemical age (−log(NO_x / NO_y)). Plotting the equivalent ratios of different organic aerosol species (LV-OOA, SV-OOA, and HOA) illustrate that the increase in OA is a result of secondary organic aerosol (SOA) formation. Within Paris the changes in the ΔOA / ΔCO are similar to those observed during other studies in London, Mexico City, and in New England, USA. Using the measured SOA volatile organic compounds (VOCs) species together with organic aerosol formation yields, we were able to predict ~50% of the measured organics. These airborne measurements during the MEGAPOLI experiment show that urban emissions contribute to the formation of OA and have an impact on aerosol composition on a regional scale